KR101775068B1 - Directional flat illuminators - Google Patents

Abstract

Optical valves or light valves, and systems and methods for 2D, 3D and / or no-spectacle stereoscopic displays that provide large-area collimated illumination from localized light sources are disclosed. The optical valve may include a stepped structure, wherein the step includes a separate extraction feature that is optically concealable with respect to light propagating in the first direction. The light propagating in the second direction may be refracted, diffracted or reflected by the feature to provide an illumination beam exiting the top surface of the optical valve. Such controlled illumination can provide enhanced multi-user no-eye stereoscopic display as well as enhanced 2D display functionality.

Description

{DIRECTIONAL FLAT ILLUMINATORS}

The present disclosure relates generally to illumination of light modulating devices and more particularly to a light modulating device that provides large area directed illumination from a localized light source for use in 2D, 3D and / guide.

Spatially multiplexed autostereoscopic displays are typically used to provide a parallax component, such as a lenticular screen or a parallax barrier, to a first and a second set of pixels Lt; RTI ID = 0.0 > array. ≪ / RTI > The parallax component directs light from each pixel set in a different direction of each to provide a first and a second viewing window in front of the display. An observer with the eye in the first viewing window can view the first image with light from the first set of pixels and an observer with the eye in the second viewing window can view the second image with light from the second set of pixels can see.

These displays have a reduced spatial resolution relative to the native resolution of the spatial light modulator, and the structure of the viewing window is also determined by the pixel aperture shape and the parallax component imaging function. For example, gaps between pixels for electrodes typically create a non-uniform viewing window. Undesirably, such a display exhibits an image flicker when the observer moves sideways relative to the display, thus limiting the viewing freedom of the display. This flicker can be reduced by defocusing the optical element, but such defocusing increases the image crosstalk level and increases the visual strain of the observer's eye. This flicker can be reduced by adjusting the shape of the pixel opening, but this change can reduce display brightness and include addressing electronics in the spatial light modulator.

According to the present disclosure, a method of guiding light using an optical valve may allow a light beam to propagate through the optical valve in a first direction, wherein the light is transmitted through the optical valve in a substantially low loss It can propagate. In addition, the optical valve can allow light rays to interact with the end surface of the optical valve, and also allows the light beam to propagate through the optical valve in the second direction, while propagating in the second direction , At least a portion of the light beam can meet the at least one extraction feature and be extracted from the optical valve.

According to another aspect of the present disclosure, a light valve for guiding light comprises a first light guiding surface, the first light guiding surface being substantially planar, and a second light guiding surface, A second light guiding surface, and may further include a plurality of guiding features and a plurality of extracting features. The extracting feature and the guiding feature may each be connected to one another and may alternate with each other and the plurality of extracting features may be arranged such that when the light is propagating in the first direction, And when light is propagating in the second direction, the light can be reflected and allowed to exit the light valve.

According to another aspect of the present disclosure, an optical valve system may include a plurality of illumination elements operatively associated with at least a first end of an optical valve, wherein the optical valve includes a first light guide Surface. The optical valve may further include a second light guiding surface facing the first light guiding surface, and may include a plurality of guiding features and a plurality of extracting features. The extraction feature and the guide feature may be connected to each other and alternate with each other. The extraction feature may allow the light to pass through with a substantially lower loss when the light is propagating in the first direction and the light is reflected and exits the light valve when the light is propagating in the second direction You can do it.

According to another aspect of the present disclosure, an optical valve includes an input side that may be located at a first end of the optical valve, a reflective side that may be located at a second end of the optical valve, A first light directing side and a second light directing side that may be located between the input side and the reflective side of the valve. The second light directing side may comprise a plurality of guiding features and a plurality of extracting features. The plurality of guide features can connect the respective extraction features.

According to another aspect of the present disclosure, a directional display system can include an illuminator array capable of providing a light beam to an optical valve. The optical valve may comprise a first light guiding surface of the optical valve, wherein the first light guiding surface may be substantially planar. The optical valve may also include a second light guiding surface of the optical valve facing the first light guiding surface, and may include a plurality of guiding features and a plurality of extracting features. The plurality of extracting features may include a first region and a second region. The extraction features of the first and second regions may have their respective orientations so that at least a portion of the light rays from the first illuminator can be directed to a first viewing window outside the optical valve, At least a portion of which can be directed to a second viewing window that is different from the first viewing window outside the optical valve.

According to another aspect of the present disclosure, an observer tracking autostereoscopic display comprises an optical valve, an array of illumination elements capable of providing light to the optical valve, an observer proximate to the viewing window of the optical valve, And a lighting controller for determining a setting for the array of lighting elements, wherein the setting can determine a first lighting stage for a first set of illuminator elements that can correspond to a first viewing window, May determine a second illumination step for a second set of illuminator elements that may correspond to a second viewing window.

In general, a light valve or an optical valve can provide large area illumination from a localized light source. The terms light valve and optical valve may be used interchangeably herein. The optical valve, in one example, may be a waveguide and may include a stepped structure, wherein the step is configured to effectively optically conceal the guided light, which may be propagating in the first direction Can be extracted. The returning light, which may be propagating in the second direction, may be refracted, diffracted, and / or reflected by the extracting feature to provide illumination that can escape from the top surface of the optical valve. Such controlled illumination can provide enhanced multi-user no-eye stereoscopic display as well as enhanced 2D display functionality.

These and other advantages and features of the present disclosure will become apparent to those skilled in the art upon a reading of this disclosure in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments are illustrated by way of example in the accompanying drawings, wherein like reference numerals designate like parts.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic top view of a conventional waveguide backlight illuminator. FIG.
1B is a schematic view showing a side view of a conventional waveguide backlit illuminator of FIG. 1A;
Figure 2a is a schematic view showing a top view of a known non-ocular stereoscopic display;
Fig. 2b is a schematic view showing a side view of the non-ocular stereoscopic display of Fig. 2a. Fig.
Figure 3a is a schematic top view of a known wedge waveguide structure.
Figure 3b is a schematic view showing a side view of the wedge-shaped waveguide structure of Figure 3a.
4A is a schematic diagram showing a top view of an optical valve according to the present disclosure;
Figure 4b is a schematic diagram illustrating a side view of the optical valve structure of Figure 5a, in accordance with the present disclosure;
5A is a schematic top view of an optical valve structure showing a directed output in the yz plane, in accordance with the present disclosure;
Figure 5b is a schematic view of a first side view of the optical valve structure of Figure 5a, in accordance with the present disclosure;
Figure 5c is a schematic diagram illustrating a second side view of the optical valve structure of Figure 5a, in accordance with the present disclosure;
6 is a schematic diagram in cross-section of an optical valve, in accordance with the present disclosure;
7A is a schematic diagram in schematic plan view of an optical valve that can be illuminated by a first illumination element and includes a curved light extraction feature, in accordance with the present disclosure;
Figure 7b is a schematic diagram in schematic plan view of an optical valve that can be illuminated by a second illumination element, in accordance with the present disclosure;
Figure 7c is a schematic diagram in schematic plan view of an optical valve, which may include a linear light extraction feature, in accordance with the present disclosure;
8 is a schematic view of a spectacle-free stereoscopic display device using an optical valve, in accordance with the present disclosure;
9 is a schematic diagram illustrating an optical valve including a planar reflective side according to the present disclosure;
10A is a schematic diagram illustrating an optical valve including a Fresnel lens, in accordance with the present disclosure;
10B is a schematic view of an optical valve comprising another Fresnel lens, in accordance with the present disclosure;
Figure 10c is a schematic diagram showing a further optical valve comprising another Fresnel lens, in accordance with the present disclosure;
11 is a schematic diagram illustrating an optical valve having a Fresnel equivalent reflecting surface according to the present disclosure;
12 is a schematic diagram illustrating an optical valve including a vertical diffuser, in accordance with the present disclosure;
Figure 13 is a schematic view in cross-section of a non-ocular stereoscopic display, in accordance with the present disclosure;
Figure 14 is a schematic view of an optical valve including separate, elongate light extraction features, in accordance with the present disclosure;
15 is a schematic diagram illustrating a cross-sectional view of an optical valve including a light extraction feature having a variable slope and height, in accordance with the present disclosure;
16A is a schematic diagram illustrating a cross-sectional view of an optical valve including a light extracting feature having a plurality of reflecting facets to a light extracting feature, in accordance with the present disclosure;
16B is a schematic diagram illustrating a cross-sectional view of an optical valve including a light extraction feature having a convex facet for the light extraction feature, in accordance with the present disclosure;
Figure 16c is a schematic diagram illustrating a cross-sectional view of an optical valve including a light extraction feature having a convex surface and a concave facet for the light extraction feature, in accordance with the present disclosure;
16D is a schematic diagram illustrating a cross-sectional view of an optical valve including a light extraction feature having an irregular facet for the light extraction feature, in accordance with the present disclosure;
Figure 16E is a schematic diagram illustrating a cross-sectional view of an optical valve including a light extraction feature arranged to provide limited scattering in the imaging direction, in accordance with the present disclosure;
17 is a schematic diagram showing an outline of a variable lateral thickness optical valve according to the present disclosure;
18 is a schematic diagram illustrating a top view of a directional display including an optical valve having a plurality of discrete light extraction features arranged to provide a reduction of the moiré pattern, in accordance with the present disclosure;
19 is a schematic diagram illustrating an option for a reflective side according to this disclosure;
20 is a schematic diagram illustrating a light path in an optical valve, in accordance with the present disclosure;
Figure 21 is a schematic diagram illustrating an optical valve comprising an additional tilt between a first light directing side and a second light directing side guide feature according to the present disclosure;
Figure 22 is a schematic diagram in section view of a light beam in an essentially parallel sided optical valve according to the present disclosure;
Figure 23 is a schematic diagram of a light beam in a tapered optical valve in cross-section, in accordance with the present disclosure;
Figure 24 is a schematic diagram illustrating a non-ocular stereoscopic display in which light extraction can be achieved by refraction in the light extraction features of the optical valve, in accordance with the present disclosure;
Figure 25 is a schematic diagram illustrating an optical valve including an air cavity, in accordance with the present disclosure;
26A is a schematic diagram illustrating a top view of an optical valve structure, in accordance with the present disclosure;
26B is a schematic diagram illustrating a side view of the optical valve structure of FIG. 26A, in accordance with the present disclosure;
Figure 27 is a graph illustrating extraction feature curves for different x offsets, in accordance with the present disclosure;
28 is a graph showing the tilt angle from the z-axis of the reflective surface of the extraction feature as a function of y-position along the feature, in accordance with the present disclosure;
29 illustrates divergent light propagation from a planar end surface, in accordance with the present disclosure;
30A is a graph showing an extractor curve and a facet angle for a divergent optical valve having a planar upper surface, in accordance with the present disclosure;
Figure 30B is a graph depicting the extractor curves and surface angles for a diverging optical valve having a planar upper surface, in accordance with the present disclosure;
31 is a schematic diagram of a stereoscopic display embodiment showing how the left and right eye images are displayed in synchronism with the first and second illumination light sources, respectively, in accordance with the present disclosure;
32 is a schematic diagram of a display embodiment, in accordance with the present disclosure, showing how an image can be selectively presented to a user without being presented to others.
33 is a block diagram of an apparatus according to the present disclosure for providing an input to a control system that substantially synchronizes the device detected by the onboard device and how the head or eye position displays the left eye and right eye images on the non- Fig.
Figure 34 illustrates how multiple viewer stereoscopic viewing can be provided using a detector to locate the eye and thereby synchronize the illumination LEDs for the left and right eye views, in accordance with the present disclosure. schematic.

Generally, in this disclosure, a method of guiding light using an optical valve may allow light to propagate through the optical valve in a first direction, wherein the light is substantially lower in the first direction It can propagate by loss. In addition, the optical valve can allow light rays to interact with the end surface of the optical valve, and also allows the light beam to propagate through the optical valve in the second direction, while propagating in the second direction , At least a portion of the light beam can meet the at least one extraction feature and be extracted from the optical valve.

According to another aspect of the present disclosure, a light valve for guiding light comprises a first light guiding surface, the first light guiding surface being substantially planar, and a second light guiding surface, A second light guiding surface, and may further include a plurality of guiding features and a plurality of extracting features. The extracting feature and the guiding feature may each be connected to one another and may alternate with each other and the plurality of extracting features may be arranged such that when the light is propagating in the first direction, And when light is propagating in the second direction, the light can be reflected and allowed to exit the light valve.

According to another aspect of the present disclosure, an optical valve system may include a plurality of illumination elements operatively associated with at least a first end of an optical valve, wherein the optical valve includes a first light guide Surface. The optical valve may also include a second light guiding surface facing the first light guiding surface, and may include a plurality of guiding features and a plurality of extracting features. The extraction feature and the guide feature may be connected to each other and alternate with each other. The extraction feature may allow the light to pass through with a substantially lower loss when the light is propagating in the first direction and the light is reflected and exits the light valve when the light is propagating in the second direction You can do it.

According to another aspect of the present disclosure, an optical valve includes an input side that may be located at a first end of the optical valve, a reflective side that may be located at a second end of the optical valve, A first light directing side and a second light directing side that may be located between the input side and the reflective side of the valve. The second light directing side may comprise a plurality of guiding features and a plurality of extracting features. The plurality of guide features can connect the respective extraction features.

According to another aspect of the present disclosure, a directional display system can include an illuminator array capable of providing a light beam to an optical valve. The optical valve may comprise a first light guiding surface of the optical valve, wherein the first light guiding surface may be substantially planar. The optical valve may also include a second light guiding surface of the optical valve facing the first light guiding surface, and may include a plurality of guiding features and a plurality of extracting features. The plurality of extracting features may include a first region and a second region. The extraction features of the first and second regions may have their respective orientations so that at least a portion of the light rays from the first illuminator can be directed to a first viewing window outside the optical valve, At least a portion of which can be directed to a second viewing window that is different from the first viewing window outside the optical valve.

According to another aspect of the present disclosure, an observer tracking autostereoscopic display comprises an optical valve, an array of illumination elements capable of providing light to the optical valve, an observer proximate to the viewing window of the optical valve, And a lighting controller for determining a setting for the array of lighting elements, wherein the setting can determine a first lighting stage for a first set of illuminator elements that can correspond to a first viewing window, May determine a second illumination step for a second set of illuminator elements that may correspond to a second viewing window.

In general, a light valve or an optical valve can provide large area illumination from a localized light source. The terms light valve and optical valve may be used interchangeably herein. The optical valve, in one example, may be a waveguide and may include a stepped structure, wherein the step is configured to effectively optically conceal the guided light, which may be propagating in the first direction Can be extracted. The returning light, which may be propagating in the second direction, may be refracted, diffracted, and / or reflected by the extracting feature to provide illumination that can escape from the top surface of the optical valve. Such controlled illumination can provide enhanced multi-user no-eye stereoscopic display as well as enhanced 2D display functionality.

In general, an optical valve may be an optical structure or any type of optical device capable of guiding and / or directing light. Light can propagate from the input side to the reflective side in the first direction in the optical valve and can be transmitted substantially without loss. The light can be reflected at the reflective side and propagate in the second direction substantially opposite to the first direction. When light propagates in the second direction, the light can enter the light extracting feature and extract or redirect light outside the optical valve. In other words, the optical valve can allow light to propagate in a first direction and allow light to be extracted while propagating in a second direction.

In one embodiment, the optical valve can function as an optical valve directional backlight and achieve time sequential directional illumination of a large display area. The time-multiplexed spectacles stereoscopic display advantageously directs light from substantially all pixels of the spatial light modulator in a first time slot to a first viewing window and directs light from substantially all pixels of the spatial light modulator in a second time slot By directing the light to the second viewing window, the spatial resolution of the spectacles stereoscopic display can be improved. As such, an observer, who is arranged to receive light in the first and second viewing windows, may view a full resolution image across the display over a plurality of time slots. The time-multiplexed display can achieve directional illumination by directing the illuminator array through a substantially transparent time-multiplexed spatial light modulator using a directional optical element, wherein the directional optical system is substantially parallel to the plane of the illuminator array To form an image. In addition, the uniformity of the viewing window may advantageously be independent of the arrangement of pixels in the spatial light modulator. Advantageously, such a display can provide an observer tracking display with low flicker and low level crosstalk to a moving observer.

In order to achieve high uniformity in the window plane, it may be desirable to provide an array of lighting elements with high spatial uniformity. For example, an illuminator element of a time-sequential illumination system can be provided by pixels of a spatial light modulator having a size of approximately 100 micrometers with a lens array. However, such pixels may suffer the same difficulty as for a spatially multiplexed display. In addition, such devices can have low efficiency and high unit cost, and require additional display components.

Conveniently, high window plane uniformity can be achieved, for example, by a macroscopic illuminator, which is an optical element that can be about 1 mm or more. However, an increase in the size of the illuminator element may mean that the size of the directional optical element may increase proportionally. For example, a back working distance of approximately 200 mm can be obtained by an illuminator of approximately 16 mm width, which is imaged in a viewing window of approximately 65 mm in width. As such, the increased thickness of the optical element can interfere with useful applications, for example, for mobile displays or large area displays.

In addition, an optical element that is thinner than the back working distance of the optical element can be used to direct the light from the macromer to the window plane. It can be discussed in relation to the optical valve illuminator that it may be related to the thickness of the optical valve in the z direction and may be in the range of approximately 0.1 mm to 25 mm. Such a display may use an array of facets that are configured to extract light propagating in a second direction in a substantially parallel optical valve.

The embodiments herein can provide a non-ocular stereoscopic display having a large-area thin structure. In addition, as will be described, the optical valve of the present disclosure can achieve a thin optical element with a large rear working distance. To provide a directional display comprising a non-ocular stereoscopic display, such elements can be used in a directional backlight. In addition, one embodiment can provide a controlled illuminator for efficient spectacles stereoscopic display. In addition, one embodiment may be directed to a directional display that may include a directional backlight device and a directional backlight device. Such a device can be used for non-eyeglass stereoscopic displays, privacy displays and other directional display applications.

In one embodiment, the optical functionality of the directional backlight can be provided by the non-linear light extraction feature that can be incorporated into the optical valve structure, thereby reducing cost and complexity. Advantageously, a combination of optical functions in the extraction feature may be provided to reduce the number of additional optical films that can be used to provide the viewing window from the illumination structure. The uniformity of the illumination of the display can be increased compared to the linear extraction feature. In addition, since the deflection of the edge reflector can be reduced, the size of the bezel of the directional backlight can be reduced and the visual appearance of the bezel can be improved. Advantageously, moire between the directional backlight and the panel can be reduced. In addition, in order to increase the degree of viewing freedom, the aberration of the display can be optimized for a range of viewing positions.

It should be noted that embodiments of the present disclosure can be used in various optical systems, display systems, and projection systems. Embodiments may include various types of projectors, projection systems, optical elements, displays, microdisplays, computer systems, processors, self-contained projector systems, visual and / or audio visual systems, and electrical and / It can work together. Aspects of the present disclosure may be used in virtually any device related to any device that may, in fact, include optical and electrical devices, optical systems, display systems, entertainment systems, presentation systems, or any type of optical system. Accordingly, embodiments of the present disclosure may be used in optical systems, devices used in visual and / or optical presentations, visual peripherals, and the like, and in a number of computing environments.

It is to be understood that this disclosure is not limited to the details of specific configurations shown in its application or manufacture, since this disclosure allows other embodiments before describing the disclosed embodiments in detail. Moreover, aspects of the present disclosure may be described in terms of different combinations and configurations to define their own unique embodiments. Also, the terminology used herein is for the purpose of description and is not limiting.

1A and 1B are schematic views showing a top view and a side view of a conventional waveguide backlight illuminator, respectively. The top view 150 of FIG. 1A includes an LED 155 that can be used to illuminate the wedge-shaped waveguide 160. Wedge shaped waveguides with scatter features are routinely used in LCD lighting. The top view 150 is shown in the xy plane.

A side view 100 of FIG. 1B is shown in the xz plane and includes LED 105, waveguide 110, LCD 120, diffuser 130, and reflective element 140. A side view 100 of FIG. 1B is an alternative view of the top view 150 of FIG. 1A. Accordingly, the LED 105 of FIG. 1B may correspond to the LED 155, and the waveguide 110 of FIG. 1B may correspond to the waveguide 160 of FIG. 1A.

The LED 105 can illuminate the thicker edge 107 of the waveguide 110 and light can propagate within the waveguide 110, as shown in FIG. 1B. A portion of the propagating light meets the reflective element 140 periodically, such as at point 145, which can scatter the light beam. Scattered light rays having a propagating angle exceeding the critical angle of the waveguide 110 escape and pass through the diffuser 130 and then illuminate the LCD 120. As the light proceeds toward the thin end 109 of the waveguide 110, the remaining scattered light rays continue to be compressed by the wedge profile. Until most of the illumination light exits the waveguide 110, the light meets more and more scatter features at points 146 and 147 in the waveguide 110. In this manner, progressive light leakage spreads the light from the localized light source along the x-axis of the waveguide 110 to illuminate the LCD 120. The LEDs 155 can be disposed adjacent to each other, as shown in Fig. 1A, so that light can propagate along the y-axis in the direction of the waveguide that is orthogonal to the wedge profile of the waveguide. As illustrated in FIG. 1B, a diffuser 130 may also be used to diffuse the illumination.

Although this conventional approach provides illumination, the exit ray angle of light is not controlled and directed. Without the control of illumination, efficiency, privacy and opportunities for stereoscopic applications without glasses are not possible.

Figs. 2A and 2B are schematic views showing a top view and a side view of a known spectacles stereoscopic display. Fig. A top view 250 of FIG. 2A is illustrated in the xy plane and includes LEDs 255a and 255b that may be used to illuminate the waveguide 210. FIG. 2B is shown in the xz plane and includes LEDs 205a and 205b, LCD 220, 3M film 230, waveguide 210, and reflective element 240. In addition, . Side view 200 of FIG. 2b is an alternative view of top view 250 of FIG. 2a. Accordingly, the LEDs 205a and 205b of FIG. 2b may correspond to the LEDs 255a and 255b of FIG. 2a, and the waveguide 110 of FIG. 1b may correspond to the waveguide 260 of FIG. 2a.

More recently, output lighting with angle control has been developed, as discussed in U.S. Patent No. 7,750,982 (Nelson et al., Incorporated herein by reference). In this known example, LEDs (255a and 255b, and 205a and 205b, respectively) are positioned to the left and right of the waveguide and can be independently modulated, as illustrated in Figures 2A and 2B. As shown in FIG. 2B, the light emitted from the right LED 205b propagates along a double wedged waveguide 210, and some of the light exceeds the critical angle and the total internal reflection (TIR) fails Gradually increases his ray angle until. These rays then exit the waveguide and propagate out towards the display in a narrow angular range close to 90 degrees to the guide normal or z-axis. A micro-prism film, illustrated as a 3M film 230 in FIG. 2B, having an integral lens positioned between the waveguide 210 and the LCD 220, directs this light to a vertical It directs along the z-axis as the angle spreads to the propagation.

Continuing the discussion of FIG. 2B, by placing the LCD 220 directly above the 3M film 230, the entirely illuminated LCD is seen only in the left eye when viewing the display vertically. This image lasts only in the left eye, because the display is rotated around the vertical until the display begins to appear in the right eye. At this point, the display looks like a conventional 2D display. A symmetrical situation is obtained in the right eye with respect to the light emitted from the left LED 205a of FIG. 2B. Modulating the left and right eye LEDs 205a and 205b in synchronization with the alternate left and right eye images supplied to the display allows the viewer to view the high resolution stereoscopic view when viewed from the vertical. Rotating the display away from vertical provides a 2D image, and when the left eye stereoscopic image is viewed in the right eye and vice versa (caused by a more conventional lenticular screen or parallax barrier) (pseudoscopic sensation). In addition, the 3D image is a full resolution unlike the conventional method, and when all the LEDs are turned on, it can basically become a conventional 2D display. The known stereoscopic display solution is limited in that it only allows two beams to be controlled independently and thus hinders privacy-efficient illumination mode and head-motion freedom in a non-eyeglass stereoscopic system capable of enabling multiple independently modulated beams. .

3A and 3B are schematic views showing a top view and a side view of another known spectacle-free stereoscopic display. The top view 350 of FIG. 3A is illustrated in the xy plane and includes an LED 355 that can be used to illuminate the wedge-shaped waveguide 360. As shown in FIG. 3A, the wedge-shaped waveguide 360 may have a reflecting corrugated surface 362. In addition, a side view 300 of FIG. 3B is shown in the xz plane and includes an LED 305, an LCD 320, a redirection film 330, and a waveguide 310. A side view 300 of FIG. 3b is an alternative view of the top view 350 of FIG. 3a. 3B may correspond to the LED 355 of FIG. 3A, and the wedge-shaped waveguide 310 of FIG. 3B may correspond to the wedge-shaped waveguide 360 of FIG. 3A. Similar to the waveguides of FIGS. 1A, 1B, 2A and 2B, the wedge-shaped waveguide 310 of FIG. 3B also has a thin end 307 and a thick end 309.

As shown in FIGS. 3A and 3B, a wedge-shaped waveguide may be used, as disclosed in U.S. Patent No. 7,660,047 (Travis, incorporated herein by reference in its entirety). The approach of Figures 3a and 3b utilizes a single LED emitter capable of representing a small optical extent or etendue.

The wedge-shaped waveguide may provide conventional collimation in the xy plane of the waveguide and may utilize the xz parallelism provided by the gradual leakage of the wedge-shaped waveguide through TIR failure. In addition, xy parallelism in reflection can be performed using an inverse parallel propagation beam to leak downwards along the same waveguide and forward propagation for beam expansion. As shown in FIGS. 3A and 3B, a tilted, curved reflecting edge surface provides an angular bias to collimation and reflection.

One problem with the wedge-shaped waveguides of Figs. 3a and 3b is that they must deflect the excited illumination beam away from the waveguide surface. This is done efficiently and uniformly using complex films. In addition, the symmetrical nature of the stand-alone wedge means that leakage can occur at both the upper surface and the lower surface. In addition, diffusion of the internal propagating light angle is reduced and ultimately increases the thickness of the wedge for any given LED light source. One additional problem relates to the reflecting edge, which must be wrinkled to avoid uneven illumination near this edge. These wrinkles are costly, because they must meet stringent design tolerances.

In general, the wedge-shaped waveguide may not function as a valve. Light that can propagate from the thin end to the thick end of the wedge-shaped waveguide can be returned without extraction if reflected directly from the thick end. It is possible to propagate backward at an angle high enough to allow light to be extracted through angle adjustment by reflection from mainly an inclined or corrugated end mirror.

Generally, for both optical valves and wedge-shaped waveguide illuminated displays, for example, commonly owned US Patent Application Publication No. 2009/0160757 entitled " Intra-pixel Illumination System & By providing a locally controlled color illumination to the pixels to eliminate the need for a color filter array ("CFA"), as disclosed in U.S. Patent Application Serial No. 10 / The efficiency can be improved by concentrating the light only on the existing region. A privacy application can also be provided by focusing the light only on the area where the viewer's eyes are present, because the light that illuminates does not reach the eyes of the potential peepers. It is possible to transmit the stereoscopic information without modifying the illuminating light individually reaching the left and right eyes in synchronism with the presentation of the left eye and right eye images and without requiring eyewear. For the handheld 3D device this latter non-eyeglass stereo method can be used.

4A and 4B are schematic views showing a top view and a side view, respectively, of an embodiment of the optical valve. In general, the embodiment of Figures 4A and 4B can act as an optical valve. The optical valves of Figs. 4A and 4B are not limitations, but can be referred to for the sake of discussion only.

4A and 4B are schematic views showing a top view and a side view, respectively, of an embodiment of the optical valve. The top view 450 of FIG. 4A is illustrated in the xy plane and includes an LED 405 that may be used to illuminate the optical valve 410. Although LEDs are discussed as light sources in connection with the embodiments discussed herein, any light source may be used, such as a laser light source, a local field emission source, an organic light emitter array, etc. have. 4B is shown in the xz plane and includes an LED 405, an LCD 420, an extraction feature 430, and an optical valve 410. A side view 400 of FIG. 4b is an alternative view of the top view 450 of FIG. 4a. Accordingly, the LEDs 405 of Figs. 4A and 4B can correspond to each other, and the optical valves 410 of Figs. 4A and 4B can correspond to each other. In addition, in Figure 4b, the optical valve 410 may have a thin end 407 and a thick end 409. Although the LCD 420 may be referred to herein for discussion, other displays, including LCOS, DLP devices, may be used because the illuminator can operate in reflection.

4A and 4B, the light propagating in the first direction can be guided through the optical valve 410 without much loss, and the light propagating in the second direction can be guided through the extraction feature 430 Can be extracted from the optical valve 410. The extraction feature 430 will be discussed in greater detail herein. The light can propagate in a first direction that can be from the thin end 407 to the thick end 409 of the optical valve 410, as shown in FIG. 4B. In addition, after reflecting from the end of the optical valve 410, the light can propagate in the second direction, where the second direction can be from the thick end 409 to the thin end 407. When the light travels in the second direction, the light can meet the extraction feature 430 and be extracted from the optical valve 410 towards the LCD 420. In addition, the extraction feature can be effectively optically concealed at the elevation of the optical valve with respect to light propagating in the first direction.

Continuing the discussion of optical valve 410 in Figure 4b, light enters the first end, e. G., The thin end 407 of Figure 4b, propagates along the length of the optical valve, 4b and propagate along the length of the optical valve toward the first end and at some point along the length of the optical valve and the light propagates along the length of the optical valve to the reciprocal of the extraction feature 430 And can be extracted from the optical valve through the action.

Continuing the discussion of this embodiment, the light can be homogenized and expanded as it propagates in the first direction before being reflected from the non-planar surface, and extracted while propagating in the second direction. The non-planar surface can function as a cylindrical lens that allows light to form an image of the light source on the window plane. In one example, the light source imaging can be accomplished by using a cylindrical reflective cross-sectional surface similar to a wedge-shaped waveguide, without the need to use high cost wrinkles. By way of comparison, the reflective section of the wedge-shaped waveguide in US Pat. No. 7,660,047 (Travis) must be wrinkled.

The optical valve may be a freestanding, single molded unit having a thickness that can be adjusted appropriately for different display platforms. In addition, the trade-off may be a loss of optical efficiency as the thickness decreases. In addition, a relatively low thickness and low cost eyeglass stereoscopic display can be achieved, and the number of optical elements used in a spectacles stereoscopic display can be reduced while improving optical quality. In addition, in one embodiment, the size of the edge bezel area or the appropriate width of the optical valve can be reduced to reduce the volume. The extraction feature does not have a substantially light directing function with respect to light passing through the optical valve from the first input side to the second reflective side and thus a long rear working distance of the light reflective side can be achieved and also a small thickness Can also be achieved. In addition, introducing a curved surface to the extraction feature can functionally replace the curved end surface, making the final external dimensions of the optical valve structure better fit with small handheld devices. Extraction features with curved surfaces will be discussed in greater detail herein.

As discussed above, the structure of one embodiment is shown in Figs. 4A and 4B, and includes two or more LED emitters at the thin end 407 and an optical valve 402 having a reflective curved surface at the other end 409 or at the reflective end . As shown in Figs. 4A and 4B, light entering the optical valve structure can propagate along the x-direction and extend along the y-direction. The extraction feature 430 may not affect the light and may not affect how the light can be guided because the extraction feature 430 may be selected from a ray that can not exceed the critical angle & Because it can be optically concealed, where the z-axis

? c = sin ^-1 (1 / n)

And n is the refractive index of the optical valve material. The xz angular profile of the light may remain substantially unchanged unlike the wedge-shaped waveguide structures described for Figs. 3a and 3b. At the farthest away from the light source, or at the thick end 409 of the optical valve 410, the light may be incident on an end surface that is substantially parallel to the z-axis but may be curved in the xy plane. This curved surface can function to image light along angles in the same xy plane while substantially maintaining the orthogonal xz angle profile. The light can form a diverging beam, lose light or form a converging beam and can not illuminate the edge, thus making a large bezel or oversize properly.

) 및 안내된 광의 오프셋 각도 ψ를 유지할 수 있지만, 안내된 광의 오프셋 각도 ψ는 광이 -x 축이 아니라 z-축에 가깝게 전파하게 할 수 있다. 대략 45° 반사는 또한 대략 광의 중심을 대략 Φ=0°일 수 있는 xz 평면에서의 출구면의 법선에 오도록 할 수 있다. xz 각도 프로파일이 약간 수정될 수 있는데, 그 이유는 추출 특징부 표면에 입사하는 높은 각도의 광선이 TIR 실패로 인해 감쇠될 수 있다. 한 예에서, x-축으로부터 대략 -50도와 대략 5도 사이에 있을 수 있는 광선이 양호한 효율로 반사될 수 있고, 대략 5도 초과일 수 있는 광선은 추출 표면을 통해 이탈하여 광학적으로 손실될 수 있다. 광학적으로 손실된 광선은 높은 각도의 광선일 수 있다. 하부를 은도금하는 것은 높은 각도의 광의 추출 효율을 향상시킬 수 있으며, 이는 광을 안내하는 동안의 전파 손실에 대한 대가일 수 있다. 안내된 광의 오프셋 각도 ψ에 대해서는 적어도 도 5a, 도 5b 및 도 5c와 관련하여 더 상세히 논의할 것이다.An offset along the y-axis of the original light source input from the symmetry axis of the structure may cause the approximately parallelized return light in the second direction to propagate to an angle ~ x with respect to the -x axis. The return beam can be reflected from the surface of the extraction feature, which can cause deflection towards the z-axis and extraction from the waveguide. Reflections from the approximately 45 ° oriented surface of the extraction feature are substantially parallel to the xz angular spreading [theta] / n

) And the offset angle? Of the guided light, but the offset angle? Of the guided light can cause the light to propagate close to the z-axis instead of the -x axis. The approximately 45 [deg.] Reflection can also cause the center of approximately the light to come to the normal of the exit plane in the xz plane, which may be approximately [phi] = 0 [deg.]. The xz angle profile can be modified slightly because the high angle of light incident on the extraction feature surface can be attenuated due to TIR failure. In one example, light rays, which may be between about -50 and about 5 degrees from the x-axis, can be reflected with good efficiency, and light rays that may be greater than about 5 degrees can be optically lost have. The optically lost ray may be a high angle ray. Silver plating of the bottom can improve the extraction efficiency of high angle light, which can be a price for propagation loss while guiding light. The offset angle? Of the guided light will be discussed in greater detail at least with respect to Figures 5A, 5B and 5C.

5a is a schematic view showing a top view of an optical valve structure showing a directed output in the yz plane, Fig. 5b is a schematic view showing a first side view of the optical valve structure of Fig. 5a, Fig. 5c is a cross- Fig.

The top view 550 of FIG. 5A is illustrated in the xy plane and includes an LED 505 that can be used to illuminate the optical valve 510. A second side view 500 of FIG. 5c is shown in the xz plane and includes LED 505, LCD 520, and optical valve 510. 5B is an alternative view of the top view 550 of FIG. 5A and also includes an LED 505, an LCD 520, an extraction feature 530, and an optical valve 510. Accordingly, the LEDs 505 of Figs. 5A, 5B and 5C may correspond to each other, and the optical valves 510 of Figs. 5A, 5B and 5C may correspond to each other. In addition, as shown in FIG. 5B, the optical valve 510 may have a thin end 507 and a thick end 509. Thus, the thick end 509 can form a concave or convex mirror.

The thickness t of the entrance of the optical valve 510 and the thickness T of the optical valve 510 may each be determined at least by the tendency and efficiency in the system, as illustrated in Fig. 5C. The tendency in the system in the yz plane is determined by the vertical y range of the exit pupil or eyebox, as shown in Figure 5b. As an example, it may be desirable for the vertical window extent to be approximately? / 2, where? Can be approximately the distance between the eye and the display (typically 300 mm). The xz angular range [theta] may be approximately 2.tan ^-1 (1/4) or approximately 30 [deg.], which can be converted to an internal xz angle of approximately [theta] / n diffusions of approximately 20 [deg.] about the x- Typical output diffusions of LEDs in air can be about 100 °, and can be about 65 ° in a waveguide. Thus, for the sake of rough coincidence, the LED angular range becomes approximately half. Assuming that a suitable beam spreader, such as a tapered waveguide, is used, etendue preservation can define that the approximate size t of the waveguide entrance can be approximately twice the size of the LED light emitting area. A typical LED for a small platform may be approximately 0.5 mm wide, which can provide approximately the size of the inlet opening as approximately t = ~ 1 mm.

A ratio of the exit opening size T to the inlet size t may be used to determine the loss of efficiency because the returning light impinging on the entrance opening may be effectively lost from the system. Then, the minimum size may be approximately 2 mm for approximately 50% efficiency, but T ~ 3 mm may provide better efficiency / thickness tradeoffs.

The number of extraction features can be limited primarily by the shape of the extraction features obtained after manufacture. The actual extraction features may include manufacturing errors from using actual manufacturing methods. These errors can typically have a finite size, for example, related to the size of the cutting tool making the mold. In case the extraction feature is small, the error can be a greater proportion of the total extraction feature and can lead to non-optimal performance. As such, a reasonable size for the extraction feature can be selected such that the extraction feature size can match the expected final shape or fidelity. The smaller the number of extraction features, the larger the feature size, and the lesser the edge is. The rounded edge may tend to expand the angular range of light propagating within the optical valve and may cause unwanted leakage. Assuming a practicable step size delta of approximately 10 [mu] m, the number of steps N may be approximately (T-t) / delta to 200. In the example of a mobile phone display in landscape stereoscopic mode, the step pitch p may be d / Ns ~ 250 [mu] m. A typical mobile phone may have a 78 μm pixel pitch, so diffusion of output light along the x-axis can be introduced to avoid the moiré effect. A diffusing angle of approximately 30 [deg.] May suffice to primarily preserve the vertical extent of the exit aperture and scramble the outgoing optical field. To achieve this effect, for example, 1D holographic diffusers from Luminit (a company based in Torrance, CA) can be used.

A curved mirrored surface can function similar to a 1D imaging element. A localized light box or exit beam can be formed in the viewer's plane through one-dimensional imaging of the individual LEDs. Assuming a minimal sag of the curved reflective surface (which may be referred to as a thin lens assumption), the imaging conditions are described by the approximate general formula 1 / u + 1 / v = 1 / f . Where f is the focal length of the curved reflective surface and may be equal to one-half of the curvature radius r, u is the distance between the LED and the end face, and v is the optical path length to the viewer, . Then the radius of curvature can be:

For a typical mobile phone value, r may be approximately 90 mm.

In other cases where the deflection of the curved surface is significant, the radius of curvature may be:

The embodiment illustrated in Figures 5A, 5B, and 5C may create an eye box that may in fact be an enlarged version of the LED. Again from a geometrical lens standpoint, the ratio Σ / s of the eye box size can be approximately equal to the geometric ratio nΔ / d~5. The position of the eye box can be similarly scaled from the approximate LED position that can be determined by? /? =? / S ~ 5. To provide head positioning flexibility, the eye box at the minimum clearance between the light emitting areas of the two LEDs may be approximately the inter-ocular distance or approximately 65 mm wide. In this exemplary case, each LED light emitting area can extend from the middle of the thin end to about 65/5 or about 13 mm. The curved cylindrical lens surface can be replaced by a Fresnel equivalent, as shown in Figure 11, which will be discussed further herein. However, this can reduce the extent to which the end surface can exceed the final display area, but it can also increase the unit cost.

Fig. 6 is a schematic view showing another embodiment of the optical valve in a sectional view. Fig. 6 is a cross-sectional view of an embodiment including an optical valve 601, which may be a transparent material. 6, optical valve 601 includes an illumination input side 602, a reflective side 604, a first planar light-oriented side 606, and a guide feature 610 and a light extraction feature (not shown) 612). ≪ / RTI > 6, the light rays 616 from the illumination element 614 of the array of illumination elements 615 are substantially parallel to the inner total reflection and guiding features 606 by the side surfaces 606 in the optical valve 601 610 to the reflective side 604, which can be mirror-finished. The array of illumination elements 615, in one example, may be an addressable LED array. Generally, in Figures 6 to 25, like numbered elements may correspond to one another. For example, the optical valve in FIG. 6 may be denoted by 601, the optical valve in FIG. 7A may be denoted by 701, the optical valve of FIG. 13 may denoted by 1301, and so on to be.

6, light 618 may be reflected by side surface 604 and may also be substantially guided by internal total reflection at side surface 604 within optical valve 601, And can be reflected by the guide feature 612. The light beam 618 that is incident on the extraction feature 612 may be deflected away from the guiding mode of the optical valve and may be substantially deflected through the side surface 604, To an optical pupil that can form the viewing window 626 of the viewing window. The width of the viewing window 626 can be determined primarily by the size of the illuminator, the output design distance, and the optical power at the side 604 and features 612. The height of the viewing window can be determined primarily by the reflective cone angle of features 612 and the input of the lighting cone angle on the input side.

The optical valve of FIG. 6 may be used, for example, by molding on one side or by attaching a molded film comprising features 610, 512 to a wedge-shaped structure having ends 602, 604 . The optical valve 601 may be formed using a material such as glass or a polymer material such as acrylic or PET (not limited to these), either singly or in combination. Advantageously, the optical valve of this embodiment can be formed with a low unit price and a high transmittance.

Figure 7a is a schematic diagram in schematic plan view of an optical valve illuminated by a first illumination element and including a curved light extraction feature. 7A is a top plan view of additional guidance of light from a light emitting element 714 at the optical valve 701. FIG. Each output beam may be directed from its respective illuminator 714 towards the same viewing window 726. [ As such, light 730 in FIG. 7A may intersect light 720 in window 726, or may have different heights in the window, as shown by light 732. The sides 722 and 724 of the optical valve can be transparent, mirrored, serrated, blackened surfaces, and the like.

7A, the light extracting feature 712 may be elongate and curved and the orientation of the light extracting feature 712 in the first region 734 of the light directing side 708 may be the same as the light extracting feature 712. [ May be different from the orientation of the light extracting feature 712 in the second region 736 of the oriented side 708.

Fig. 7B is a schematic diagram showing a schematic plan view of an optical valve illuminated by a second illumination element. Fig. Figure 7b includes rays 740 and 742 from the second illuminator element 738 of the array 715. [ The curvature and light extraction features of the mirror at side 704 cooperate to create a second viewing window 744 having a ray from illuminator 738 that may be laterally separated from viewing window 726 .

The embodiment of Figures 7A and 7B may provide a real image of the illuminator element 714 in the viewing window 726 while this actual image may have a refractive index at the reflective side 704 and a refractive index at the area 734, Can be formed by the cooperation of light refraction forces that may arise due to the different orientations of the elongate light extraction features 712 between the regions < RTI ID = 0.0 > 736 < / RTI & 7A and 7B can achieve improved aberration of the imaging of the light emitting element 714 relative to the lateral position in the viewing window 726. In addition, The improved aberration can achieve extended viewing freedom of the spectacles stereoscopic display, while achieving a low crosstalk level. In one example, the extended viewing freedom may include a larger angle at which 3D can be viewed with good performance, or a lower crosstalk that may be less than about 5%.

7C is a schematic diagram showing a schematic plan view of an optical valve that may include a linear light extraction feature. Figure 7c shows a similar arrangement to Figures 4a and 4b in which the light extracting features are linear and substantially parallel to one another. The embodiment of Figure 7c may provide substantially uniform illumination over the display surface and may be more convenient to manufacture than the curved surface features of Figures 7a and 7b.

8 is a schematic view showing an eyeglass stereoscopic display apparatus using an optical valve. Figure 8 shows an observer tracking non-eyeglass stereoscopic display device. 8, the array of illumination elements 815 and the optical valve 801 may be arranged to provide an array 846 of viewing windows. A sensor 850, such as a CCD or CMOS sensor, may be used to sense the observer near the window, and an observer tracking system 852 may be used to calculate the observer position. The illuminator controller 854 can determine the correct setting of the illuminator array so that the illuminator element corresponding to the viewing window set 856 can be illuminated during the first lighting stage and the illuminator element corresponding to the viewing window set 858 And can be illuminated during the second illumination step. The controller 854 can adjust which illumination element of the array 815 is illuminated depending on the observer position. An image display may be provided by a transmissive spatial light modulator display 848 such as an LCD and positioned between the optical valve 801 and the viewing window array 846. [ In a first illumination step that may correspond to the illumination of the window array 856 a left eye image may be presented on the display 848 and in a second illumination step that may correspond to the illumination of the window array 858, May be presented on display 848. [

The embodiment of FIG. 8 can achieve wide viewing freedom of the observer-tracking non-ocular stereoscopic display with low level of flicker for moving observers. By changing the orientation of the extraction feature 812 over the optical valve, the optical quality of the window of the array 846 can be improved. Thus, in addition to crosstalk to the observer, illumination uniformity in the window plane can be optimized. This embodiment can provide a thin optical valve that can be configured as a directional backlight to bring the LCD into a thin package. In addition, the embodiment of Figure 8 may not use an additional light conditioning film, since the output may be oriented substantially in the forward direction. In addition, the efficiency of the optical valve can be varied by using generally TIR reflection rather than reflection from a metal plated surface. The light extraction may be substantially through the light directing side 804 because the light loss through the light side 808 may be substantially lower.

Figure 9 is a schematic view showing an optical valve including a planar reflective side. Figure 9 illustrates a further embodiment of an optical valve comprising a planar reflective side 904. The light extraction feature 912 may be configured to direct the light rays 960 from the light emitting element array 915 toward the window array 946. [ However, the side surface 904 may be a reflective surface, such as a mirror, which may have little to no light power, and therefore light power can be provided by the light extracting feature 912. The embodiment of Figure 9 can achieve a small total area of the optical valve that can roughly match the area of the spatial light modulator. This can reduce the total display size. Specifically, the approximate area under the deflection of the curvature of the side surface 904 can be substantially eliminated.

FIG. 10A is a schematic view showing an optical valve including a Fresnel lens, and FIG. 10B is a schematic view showing an optical valve including another Fresnel lens. FIG. 10A and 10B illustrate additional embodiments in which additional Fresnel lenses 1062 may be disposed at the output of an optical valve having planar and curved sides 1004, respectively. The Fresnel lens is configured to cooperate with the side surface 1004 and the light extraction feature 1012 to substantially direct light from the array of illumination elements 1015 toward the viewing window array (not shown) . The Fresnel lens may have a spherical or cylindrical shape, which may depend on the vertical height of the window (not shown in the figure). In addition, the optical power of the optical valve may be dispersed between the side face 1004, the light deflection feature 1012, and the Fresnel lens, which may cause the window (not shown) It is possible to reduce the deterioration of the window structure in the array and thus maintain a low level of flicker for the moving observer in the window plane while increasing viewing freedom and reducing image crosstalk.

10C is a schematic view showing a further optical valve including another Fresnel lens. 10C, the axis of the Fresnel lens 1062 may be offset relative to the center of the optical valve such that the axis 1064 of the center of the display may be at a different position relative to the axis of the lens 1066 . The embodiment of FIG. 10C can transition the nominal output light direction from the extraction feature to be more axial than otherwise. In addition, the embodiment of FIG. 10C may provide a brighter display, since vertical diffusion may not be used to provide adequate axial brightness.

11 is a schematic view showing an optical valve having an alternative reflective end; As shown in FIG. 11, the optical valve may have a curved surface or a conventional collimating wedge portion 1110 that may be replaced by a Fresnel equivalent 1120.

12 is a schematic diagram showing an optical valve including a vertical diffuser. 12 shows a vertical diffuser 1268 arranged to provide diffusion of the input light 1220 to the cone angle 1270 which can increase the vertical height of the window without significantly increasing the scatter in the horizontal direction Lt; RTI ID = 0.0 > embodiment. ≪ / RTI > In addition, the vertical viewing angle can be increased without increasing the crosstalk between adjacent windows in the array 1246. Vertical diffusers can be various types of materials, including asymmetric scattering surfaces, relief structures, lenticular screens, and the like. The vertical diffuser may be arranged to cooperate with the Fresnel lens, which may provide high display uniformity for rotation about a horizontal axis.

Fig. 13 is a schematic view showing a spectacle-free stereoscopic display in a sectional view. Fig. Figure 13 illustrates a non-eyeglass stereoscopic display comprising an optical valve 1, a Fresnel lens 1362, a vertical diffuser 1368, and a transmissive spatial light modulator 1348, And may be arranged to provide a stereoscopic viewing window 1326. [ There is a gap between the diffuser 1368 and the Fresnel lens 1362 to reduce moire beating between the structure of the spatial light modulator 1348 and the Fresnel lens 1362 and the light extraction feature 1312 Can be provided.

In some embodiments, the density of the light extracting feature 1312 in the region at the edge of the optical valve 1301 may be lower than the density in the center of the optical bed 1301. This arrangement can result in non-uniform intensity across the area of the display device. 14 is a schematic view showing an optical valve including a separate elongated light extracting feature. 14 illustrates that additional discrete elongated light extraction features 1472 may be arranged between, for example, successive light extraction features 1474, advantageously to achieve higher display intensity uniformity. .

15 is a schematic view showing a cross-sectional view of an optical valve including a light extracting feature having a variable slope and a height. 15 is a cross-sectional view of a schematic arrangement of light extracting features and guiding features 1576 and 1578, wherein the height and slope of the light extracting feature may vary across the second light directing side 1508. [ Advantageously, the height can be varied to adjust the amount of light that can be extracted from the optical valve for a particular region, while the slope can be adjusted to provide vertical diffusion characteristics.

16A is a schematic diagram showing a cross-sectional view of an optical valve including a light extracting feature having a plurality of reflecting facets for a light extracting feature. 16A is an embodiment in which the light extracting feature 1673 can be provided by a plurality of planar surfaces. 16B is a schematic diagram illustrating a cross-sectional view of an optical valve that may include a light extraction feature having a convex facet for the light extraction feature. 16B shows one configuration of the convex light extracting feature 1675, whereas FIG. 16C shows the combination of the convex light extracting feature 1675 and the concave light extracting feature 1677. FIG. 16C is a schematic view showing a cross-sectional view of an optical valve including a light extracting feature having a convex surface and a concave surface with respect to the light extracting feature. 16D is a schematic view showing a cross-sectional view of an optical valve including a light extracting feature having an uneven surface for the light extracting feature. 16D illustrates an embodiment that provides the shape of the irregularities feature 1612. FIG. The embodiments of FIGS. 16A, 16B, 16C, and 16D can provide vertical diffusion characteristics without using vertical diffuser 1668, thus reducing unit cost and complexity.

16E is a schematic diagram showing a cross-sectional view of an optical valve 1690 including a light extraction feature arranged to provide limited scattering in the imaging direction. Figure 16e shows a further embodiment in which the light extracting feature has a surface modulation 1695 at the extractor face, which may be for light diffusion and the side diffusions are arranged to be achieved in the window plane . The cone angle of diffusion can be used to provide any lateral blurring of the window structure, but may be much lower than that used for vertical diffusion. This arrangement can be used to improve window uniformity and reduce display flicker for moving observers.

17 is a schematic view showing an outline of a variable lateral thickness optical valve. 17 shows an optical valve 1701 in which the height of the extraction feature 1712 can vary over the width of the optical valve 1701 and thereby provide higher extraction uniformity over the area of the side 1706 (Not shown). Thus, the height 1778 of the feature 1712 at the edge of the optical valve 1701 may be greater than the height 1780 at the center of the optical bed 1701. In the embodiment of FIG. 17, the light guiding features 1724 may not be parallel to each other or to the surface 1706. The orientation of the feature 1712 can be adjusted to compensate for this change in the surface normal direction to the light guide feature 1710. [

18 is a schematic diagram showing a top view of a directional display including an optical valve that can have a plurality of separate light extracting features and is arranged to provide a reduction of the moiré pattern. 18 schematically illustrates a random arrangement of elongate light extraction features arranged to reduce moiré between the light extraction features and the pixilated spatial light modulator. Moire patterns can be seen when two periodic translucent structures are placed in close proximity. The introduction and random placement of the extraction features can break and / or interrupt any periodicity and reduce the visible moiré effect.

19 is a schematic diagram showing the optical imaging option provided by the curved reflective side; 19 shows three different examples of optical parallelization of the principal ray. 19 shows a converging principal ray, example b shows a collimated principal ray, and example c shows a diverging principal ray, both of which are reflected in the second direction after being reflected from the reflective side It may be spreading. 19 shows that the curvature of the reflective side 1904 can be adjusted to substantially control the collimation and / or de-collimation of the light reflected within the optical valve 1901 Giving. Advantageously, the diverging beam can provide the greatest area utilization for off-axis viewing of the optical valve 1901, as shown in Figure 19C.

20 is a schematic view showing a light path in the optical valve. The geometry of FIG. 20 can be used to determine the curvature and slope of the optical valve 2001 extraction feature that focuses the collimated principal ray at an approximate point in view plane a at distance V from the display. In addition, Fig. 20 schematically shows the surface normal and the light beam direction for the optical valve 2001 structure of this embodiment.

21 is a schematic diagram showing an optical valve including an additional tilt between the first light directing side and the second light directing side guide feature.

Figure 22 is a schematic view of a light beam in a substantially parallel sided optical valve in cross-section. 22 is a cross-sectional view of an embodiment having no tilt angle between the first light directing side 2206 and the second light directing side guiding feature 2210. [

23 is a schematic view of a light beam in a tapered optical valve in cross section; The embodiment of Figure 22 includes guiding light rays that can be incident on the light extracting feature 2212 of the light directing side 2308 (including the features 2310 and 2312) in the optical valve, Where the side surface 2206 may be substantially parallel to the guiding feature 2210. Light ray 2282 can be incident on extraction feature 2212 and deflected by a facet but can be captured by TIR at side 22206 within optical valve 2201. Light rays 2284 can be extracted as shown, but light rays 2286 can also be transmitted through the light extracting feature, and as a result can be optically lost. Providing the wedge between the feature 2310 and the side 2306 may provide additional output coupling light, as shown in FIG. In this case, the less steeply inclined light extracting feature 2312 may be arranged such that the light for all three incident rays is substantially directed back into the optical valve. Since the optical valve can be a taper that tapers to the light traveling in the direction illustrated in Fig. 23, the light rays incident on the side surface 2306 may not exceed the critical angle and thus may be output from the optical valve. In addition, the output coupling film 2388 may be arranged to redirect light near the surface of the side surface 2306 in the on-axis direction of the display. Advantageously, such an arrangement can achieve features that are more steeply sloped than optical valves with parallel sides. This feature can reflect more of the angle of the waveguide cone in the optical valve, without using an additional metal plating coating, and can therefore be more efficient.

24 is a schematic view showing a spectacles stereoscopic display in which light extraction can be achieved by refraction in the light extraction features of the optical valve. 24 illustrates a further embodiment in which the light extracting feature 2412 may be arranged to refract light at the optical valve 2401. [ The light deflection structure 2492 may include an array of prisms that may be arranged to direct the extracted light rays 2490 in a direction that may be substantially perpendicular to the panel output direction. Fresnel lens 2462 and diffuser 2468 may also be further arranged to direct light onto panel 2448 so that viewing window 2426 can be formed as previously described. In one example, the facet angle may be approximately 90 degrees. Advantageously, this embodiment can achieve a high level of light extraction from feature 2412.

25 is a schematic view showing an optical valve including an air cavity. 25 illustrates another embodiment in which the optical valve may include an air cavity 2598 having first and second light directing sides 2506 and 2508. [ The first and second light directing sides 2506 and 2508 may be arranged on the support substrates 2594 and 2596, respectively. The side surface 2506 and feature 2510 can be plated metal other than the extraction feature 2512 and thus can be extracted when the light is propagating in the second direction, but when propagating in the first direction It may not be extracted. Advantageously, this arrangement can be less easily damaged during handling than the internal total reflection waveguide optical valve 2401 of FIG.

26A and 26B are schematic views showing a top view and a side view of the optical valve structure, respectively. Figures 26a and 26b illustrate another embodiment that may utilize a surface extraction feature that may enable a planar reflecting end surface. In addition, in another embodiment, a curved rear reflector surface and curved surface extracting feature 2610 are included to avoid excessive light loss through lack of parallelization at the edges while reducing back edge outer curves . Moreover, other embodiments may divide the extraction feature into smaller isolated features to substantially avoid aliasing problems in the panel. Each feature can still be configured with a designed surface that can provide a roughly correct angle of reflection for imaging conditions without substantially affecting the guided light propagating forward.

The extraction features of the optical valve system can form a series of separated facets. The separated surface can change the propagation angle of the guided light so that the total internal reflection (TIR) at the optical valve surface can fail and the light can be extracted. In one example, the extracting feature may be separate so that the inclined feature has a first slope and may be separated by a section of the guide feature having the second slope, wherein the second slope is the inclination of the inclined feature 1 slope and a different slope.

Other functions may include directing light in a substantially predetermined manner to optimize angle-controlled illumination. In at least the discussion with reference to Figures 5 and 6, the extraction feature is assumed to be a substantially linear, uniformly inclined step that can function to convert the propagation direction from -x to z according to the tilt angle. Functions such as focusing, redirecting, spreading, etc. may be provided by one or more external films, which may include, but are not limited to, diffusers and Fresnel lenses. Including many functions in the extraction feature can reduce the unit cost and improve the performance.

In yet another embodiment, a diffuser may be included in any of the optical valve variations discussed herein. As illustrated in FIG. 5, introducing surface modulation to the extractor facet can deflect light into approximately a set of predetermined horizontal and vertical angles, which in effect can diffuse illumination light. Diffusion can be used to blur the imaging of the physical gap between the LED light emitting areas. This may also be useful for mixing light between adjacent LED light sources to minimize color non-uniformity. The spatial dimension associated with this diffusive surface modulation may be small enough so that the surface modulation may not be solved by the system or may cause spatial interference with the periodic pixels of the illuminated display. Spatial interference can be partially mitigated by making any modulation aperiodic and pseudo-random.

The extraction features of the light valve directional backlight system can form a series of separate slopes that can change the propagation angle of the guided light in such a way that the total internal reflection (TIR) at the guide surface substantially fails and allows light to escape have. The terms separated, tilted, spaced apart, etc. may be used herein to describe the configuration of the extraction features with respect to each other. In one example, the extraction features may be separated from each other by a guide feature. The secondary function may be to direct the light in a predetermined manner to optimize substantially angle-controlled illumination. At least in the discussion with respect to Figures 4A, 4B, 5A, 5B and 5C, the extracting feature comprises a substantially linear and uniformly inclined step, which can convert the propagation direction from -x to ~ z according to the tilt angle . Functions such as focusing, redirecting, spreading, etc., may be provided by one or more external films, which may include diffusers and Fresnel lenses, but may be provided by design of extraction feature profiles.

In one embodiment, the extracting feature can substantially focus the system's main beam on the viewing plane, which can avoid the use of any additional film that excludes a miniature diffuser. The primary ray of the system may be a ray substantially centered in the ray set at any position in the system. For example, light propagating from a physically small LED light source at one end of the optical valve can provide a sectorial principal ray in the xy plane that can propagate toward the end reflector. Upon reflection from the end reflector, these rays can again propagate at a modified angle in the xy plane to provide convergence, collimation or divergence, as shown in Figures 19a, 19b and 19c. Figs. 19A, 19B and 19C are schematic views showing the optical imaging option provided by the curved reflecting side surface. Fig.

The convergent principal ray as shown in Fig. 19A can move away from the edge and not illuminate the optical valve surface area, but the substantially horizontal localization of the ray extracted from the viewing plane by the substantially linear extraction feature . ≪ / RTI > The uniform illumination of the display may involve including a horizontal magnitude excess of the waveguide. The diverging light beam as shown in Fig. 19C provides light to the local eye pupil, but can also be redirected from the pillar LED to substantially fill the desired illumination area. The more rays are emitted, the less illuminant the illuminator may have, because the light may be optically lost towards the edge of the optical valve. The nearly parallel propagating principal ray, such as that shown in Figure 19b, can achieve adequate tradeoff.

The embodiment of Figure 20 is provided by way of example, not limitation, and assumes an illumination area of approximately 150 x 200 mm for the x and y dimensions. In addition, the calculation assumes that the coordinate origin is approximately centered in the middle of the display area, as shown in Fig.

The curvature and slope of the extraction feature that can be used to focus the collimated principal ray at a point in the viewer's plane can be derived from the configuration illustrated in FIG. The parallel rays can propagate back along the x-axis by the following propagation vector before encountering the extraction feature at position (x, y).

The plane of the extraction feature at this point is the surface normal vector n (x, y) that allows the reflected light to travel directly to the focal point (0, 0, V) side with a normalized propagation vector ):

V is the product of the viewing distance, which can be approximately 500 mm, and the refractive index of the waveguide, which can be approximately 1.5. In this example, V may be approximately 750 mm.

The law of reflection can indicate that the surface normal, n (x, y), which deflects the ray propagating in ki into a ray propagating in ko, is approximately:

A continuous extraction feature curve can follow a path in the xy plane that may be orthogonal to its face normal. Mathematically:

Where dx and dy can be infinitely small transitions along the curved surface. This equation can be used to obtain a local gradient of the curved surface in the xy plane.

Fig. 27 shows the extraction feature curve x (x0, y) from the center (y = 0) to the edge (y = 100 mm) of the waveguide that can be derived from the local gradient equation. the entire curve containing the negative value of y may not be used because the curve may be flat from the physical symmetry about the y-axis.

The surface normal n of the extraction feature can be described by its tilt angle to the xy plane since the surface normal orientation in the same xy plane can be determined by the curvature of the extraction feature. The surface tilt angle [theta] from the z-axis can be given as

Where k may be a conventional z-axis direction vector.

In one embodiment, n is as previously described,

Figure 28 shows the tilt angles for the three extraction features centered at approximately x = -50, 0 and 50 mm.

In another embodiment, the design can focus the diverging propagating principal ray. In one example, the design may not have a curved end surface. In this embodiment, the silver plated planar surface can reflect light and substantially retain the divergence in the xy plane of the original LED emission. This is advantageous because it allows the entrance edge to be touched by LED light sources for greater ease of manufacture, less area wasted by incomplete illumination below any curved deflection, and greater angular deflection and substantially uniform ' 2D-like & ≪ / RTI > 29 shows the divergent light propagation from the planar end surface. The geometric shape shown in FIG. 29 can provide the principal ray propagation ki at any location (x, y) as follows:

Where L may be the x-dimension of the optical valve. In this embodiment, L may be approximately 150 mm.

Continuing from the above analysis, in this case, the local gradient of the extractor curve can be:

In other words, a curve profile x (x0, y) can be derived for a curve that intersects the x-axis at x0.

Then, the extractor plane normal for the z-axis can be:

The derived extractor profile and surface tilt values are illustrated in Figures 30A and 30B.

The embodiments described herein can direct light emitted by a single axial source to a single point in the viewer ' s plane. These designs can be further optimized to accommodate multiple light sources using optical design packages such as Zemax, FRED, ASAP, and the like.

31 is a schematic diagram of a stereoscopic display system using a controlled backlight. 31 includes a viewer 3105, a right eye image 3110, a left eye image 3120, and a display system 3130. Fig. 31, the right-eye image 3110 and the left-eye image 3105 can be displayed substantially in synchronization with the first and second illumination light sources, respectively, such as LEDs. In addition, the display system 3130 and display discussed herein may be used in various types of devices, including cell phones, smart phones, PDAs, gaming systems, laptops, television systems, displays, Lt; / RTI > In the example of FIG. 31, each of the two LEDs may provide an outgoing motion or a light box that can be aligned by a viewer to individually illuminate each eye. Modulating the LED in substantially synchronized with the display system 3130 providing alternating left and right stereoscopic images may enable 3D viewing. The material cost of the display unit may be similar to the material cost of the 2D display. In addition, the efficiency of the display system 3130 when in 2D mode or when the display can be updated in a conventional manner can be significantly improved because it illuminates an area remote from the eye of the viewer 3105 The light may not be wasted.

32 is a schematic diagram of a display embodiment showing how an image can be selectively presented to a user without being presented to others. 32 includes a first viewer 3210, a second viewer 3220, and a display 3230. In the embodiment of FIG. 32, the display 3230 may provide privacy because other people can not see the display 3230 if substantially no illumination light is present. 32, the first viewer 3210 can view stereoscopic or conventional 2D images, while the second viewer 3220 at a different location, such as the next seat when using public transportation, 3210 can not see the content on the display 3230 that can be viewed.

Introducing two or more LEDs can provide multiple eye boxes, freeing head and / or device movement, and providing multiple viewer options. The position of the viewer's eye can be obtained, in one example, using an outwardly directed inboard CCD detector, which is commonly found in handheld devices and laptops. These two system functions are schematically described in Figs. 33 and 34. Fig.

33 is a schematic diagram showing how the device and head or eye position can be detected by an onboard device; Figure 33 includes a device 3310, a first orientation 3320, a second orientation 3330, a first set of illumination pupils 3325, and a second set of illumination pupils 3335. 33, the first set of illumination pupils 3325 may include images that can be synchronized with the right eye and also images that can be synchronized with the left eye. In this case, the device 3310 may be located in the first orientation 3320, and the first set of illumination pupils 3325 may include fewer images that can be synchronized with the right eye and more Number of images. 33, the device 3310 may be located in the second orientation 3330 and the second set of illumination pupils 3335 may include a smaller number of images that can be synchronized with the left eye And a larger number of images that can be synchronized with the right eye.

Continuing the discussion of Figure 33, the on-board device may be a CCD camera and may provide input to a control system that substantially automatically synchronizes displaying the left eye and right eye images on the non-eye stereoscopic display 3310 have. LED synchronization can be determined by the eye tracking input using an onboard CCD camera. In the example of FIG. 33, a device and / or a head position input can be provided to a control system that controls a plurality of LED illuminators that can be substantially synchronized with the left and right eye images alternately displayed. In addition, the stereoscopic image can be changed in accordance with the viewing angle so as to achieve motion parallax without increasing the display bandwidth.

34 is a schematic diagram showing how multi-viewer stereoscopic viewing can be provided using a detector to locate the eye and thereby substantially synchronize the illumination LEDs for the left eye and right eye views. Figure 34 includes a device 3410, a first viewer 3420 and a second viewer 3430. [ As illustrated in Figure 34, the device 3410 may be in a position as long as at least the first viewer 3420 and the second viewer 3430 are viewing the device 3410. [ In this example, a CCD camera, which may be located at device 3410, can locate the eye position of viewers 3420 and 3430. Continuing with the example of FIG. 34, the controller then moves the illumination LEDs (not shown) in the device 3410 to provide a left view through the optical valves to the left eye of the first viewer 3420 and the left eye of the second viewer 3430 in a particular direction. Can be controlled. In addition, the right eye view may be provided through the optical valve toward the right eye of the first viewer 3420 and the right eye of the second viewer 3430 in other specific directions. Although only two viewers are included in FIG. 34, more viewers can view device 3410, and two viewers are used for discussion, not for restriction.

While the described system embodiment assumes a handheld mobile platform, these examples should not be considered limiting. This controlled illumination scheme can be applied to both small and large LCD platforms, including laptops, television applications, and the like.

As used herein, the terms "substantially" and "roughly" provide industry accepted tolerances for the relativeness between their corresponding terms and / or items. Acceptable tolerances in this industry are in the range of 1 percent to less than 10 percent and correspond to component values, angles, such as, but not limited to. This relativeness between items is in the range of 1 percent to less than 10 percent.

While various embodiments in accordance with the principles set forth herein have been described above, it will be appreciated that they are provided by way of example only, and not limitation. Accordingly, the breadth and scope of the embodiment (s) should not be limited by the above exemplary embodiments, but should be limited only by the claims and their equivalents from this disclosure. In addition, while the advantages and features are provided in the described embodiments, the application of the disclosed claims is not limited to the processes and structures achieving some or all of the advantages.

In addition, section titles are provided to comply with the proposal under 37 CFR 1.77 or otherwise provide clues to the composition. These headings do not limit or characterize the invention (s) set forth in any claim that may come from this disclosure. Specifically, and by way of example, the title is referred to as "technical field ", but claims should not be limited by the phrase selected under this heading to describe so-called fields. In addition, the description of a technique in the "background art" should not be construed as an admission that a particular technique is prior art to any embodiment (s) in the present disclosure. "Content of the Invention" should not be construed as indicative of the nature of the embodiment (s) set forth in the claims set forth. In addition, the singular form "invention" in this disclosure should not be used to say that there is only one aspect of novelty in the present disclosure. A number of embodiments may be described in accordance with the limitations of the various claims from the disclosure, which limit the embodiment (s) and equivalents thereof protected by the claims accordingly. In all cases, the scope of such claims should be considered on their own based on this disclosure, but should not be construed to be limited by the subject matter described herein.

Claims (91)

In an optical display,
Light valve;
A plurality of illumination elements configured to provide light to the light valve;
A transmissive spatial light modulator arranged to be illuminated by the light valve; And
And a fixture controller for controlling the lighting element,
Wherein the light valve comprises:
A first end through which light enters the light valve and can propagate in a first direction;
A second end that is a reflective surface arranged to redirect light propagating in the first direction and propagate back toward the first end in a second direction, the second end having a concave curved reflective surface or a concave curved reflective surface Fresnel equivalent;
A first light guiding surface that extends between the first end and the second end and is planar; And
A second light guiding surface extending between the first end and the second end opposite the first light guiding surface, the second light guiding surface comprising a plurality of elongated extrusions having a curved and inclined cross-sectional profile along an elongated direction, Wherein the extracting feature and the guiding feature are alternately connected to each other and the plurality of extracting features are arranged such that when the light is propagating in the first direction, And wherein the tilted cross-sectional profile of the extraction feature is configured such that when the light is propagating in the second direction, the light is reflected and directed toward the viewing plane through the first light guide And the curvature of the extraction feature along the elongated direction of the extraction feature is greater than the curvature of the extraction feature Wherein the tilted cross-sectional profile and the curvature of the curvature of the extraction feature and the curvature of the reflective end cooperate to direct the focused light to respective viewing windows in the viewing plane by causing the light from the lighting elements to be focused. Comprising a light guiding surface,
Wherein the optical display is an observer tracking autostereoscopic display and the illuminator controller includes a first set of lighting elements corresponding to a first viewing window to provide light in a first illumination phase, And to control a second set of lighting elements corresponding to a second viewing window to provide light in a second lighting stage, the first lighting stage corresponding to a left eye image on a display, and the second lighting stage Corresponds to a right-eye image on the display. The optical display of claim 1, wherein the plurality of illumination elements is an array of addressable LEDs. The optical display of claim 1, further comprising a sensor for detecting a position of an observer proximate the viewing window of the light valve. 4. The optical display of claim 3, wherein the fixture controller is arranged to control the light elements according to the position of the observer detected by the sensor. delete delete The optical display of claim 1, wherein the second light guiding surface has a stepped configuration including the plurality of elongated extraction features, and the plurality of guiding features connect each extraction feature. The optical display of claim 1, wherein the extraction feature allows light to exit the light valve through the first light guiding surface. The optical display of claim 1, wherein the light valve is arranged to direct light entering the light valve from a lighting element to a viewing window. The optical display of claim 1, further comprising a Fresnel lens positioned to receive light from a first light guiding surface of the light valve. The optical display of claim 1, further comprising a vertical diffuser positioned to receive light from the first light guiding surface of the light valve. 12. The optical display of claim 11, wherein the vertical diffuser comprises an asymmetric scattering surface. 2. The optical display of claim 1, wherein the first end is thinner than the second end. In a directional display,
A light valve for guiding light;
An array of illumination elements configured to input light into the light valve in a first direction;
A transmissive spatial light modulator arranged to be illuminated by light exiting the light valve; And
A fixture controller arranged to control which illumination element is illuminated,
Wherein the light valve comprises:
A first light guiding surface;
A second light guide surface facing the first light guide surface; And
A reflective end arranged to redirect light propagating in the first direction through the light valve in a second direction, the reflective end being a Fresnel equivalent of a concave curved reflective surface or a concave curved reflective surface; ,
Wherein the second light guiding surface comprises a plurality of elongated extraction features and a plurality of guiding features having a curved and inclined cross-sectional profile along the elongated direction and the guiding feature and the guiding feature alternately And wherein the plurality of extraction features allow the light to pass through without loss when the light is propagating in the first direction, and wherein the tilted cross-sectional profile of the extraction feature is such that light is transmitted through the second direction So that the light can be reflected and exit the light valve through the first light guiding surface towards the viewing plane, and wherein the curvature of the extraction feature along the elongated direction is greater than the curvature of the extraction feature By allowing light from the element to be focused, the curvature of the tilted cross-sectional profile and the extraction feature, Will of which the curvature is oriented to cooperate with the focused light in each viewing window in the viewing plane,
Wherein the directional display is an observer tracking autostereoscopic display and the fixture controller includes a first set of lighting elements corresponding to a first viewing window to provide light in a first illumination phase And to control a second set of lighting elements corresponding to a second viewing window to provide light in a second lighting stage, the first lighting stage corresponding to a left eye image on a display, and the second lighting stage Corresponds to the right eye image on the display.
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